130 BOILER TESTS. 



Dimensions of Boiler No. 24. 



Diameter of shell, 48 in. 



Length between heads and length of tubes, . . . . 15 ft. 



Number of tubes 3 inches outside diameter, . . . . 49 



Area of heating surface, ........ 639 sq. ft. 



Area of grate surface, . . 24 sq. ft. 



Area through tubes, . . . . . . . . . 2 sq. ft. 



Area through flue, . . . . . . . . .1.3 sq. ft. 



Height of chimney, 55 ft. 



Width of air spaces and metal bars in grates, . Air 5-8 in., metal 7-8 in. 



Distance of grate to shell, 17 in. 



Distance of bridge wall to shell, 4 in. 



Ratio of heating surface to grate surface, . . . . 26.6 to 1 

 Ratio of grate to tube area, 11.9 to 1 



Results of Test, Boiler No. 24. 



Test No. 59. 

 Manner of start and stop and kind of run, .... Ordinary. 



Duration, 11.2 hrs. 



Coal consumed ( including wood equivalent ), . . 2,138 Ibs. 



Percentage of ash, 12 per cent. 



Water evaporated, 18,224 Ibs. 



Coal per hour, 190 Ibs. 



Coal per hour per square foot of grate, 7.9 Ibs. 



Water per hour, 1,619.9 Ibs. 



Water per hour per square foot of heating surface, . . 2.5 Ibs. 



Horse-power developed, 48.1 H. P. 



Boiler pressure, ......... 59 Ibs. 



Temperature of feed-water, ...... 210.5 deg. 



Temperature of escaping gases, . . . . . 474 deg. 



Draught suction, ......... 0.30 in. 



Water per pound of coal, ....... 8.52 Ibs. 



Water per pound of coal from and at 212 degrees, . . 8.78 Ibs. 



Water per pound of combustible from and at 212 degrees, . 9.87 Ibs. 



The test on Boiler No. 24 exhibits the performance of a 

 boiler working under unfavorable conditions and giving a low 

 economic result. Here the low rate of combustion, the high 

 temperature of the gases, and a somewhat large percentage 

 of ash, indicate the main cause of the low degree of economy. 

 The large amount of draught suction in the main flue, which 

 was 0.3 inches, is noticeable in view of the fact that the boiler 

 worked to less than its normal capacity. The reason for this 

 is seen in the small flue area, which was only one-eighteenth 

 of the grate surface. 



